US7526856B2 - Method for fabricating a magnetic head using a ferrofluid mask - Google Patents
Method for fabricating a magnetic head using a ferrofluid mask Download PDFInfo
- Publication number
- US7526856B2 US7526856B2 US11/391,069 US39106906A US7526856B2 US 7526856 B2 US7526856 B2 US 7526856B2 US 39106906 A US39106906 A US 39106906A US 7526856 B2 US7526856 B2 US 7526856B2
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- United States
- Prior art keywords
- ferrofluid
- photoresist
- mask
- slider
- selected area
- Prior art date
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- Expired - Fee Related, expires
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Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3109—Details
- G11B5/3116—Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/44—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids
- H01F1/445—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids the magnetic component being a compound, e.g. Fe3O4
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/32—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying conductive, insulating or magnetic material on a magnetic film, specially adapted for a thin magnetic film
- H01F41/34—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying conductive, insulating or magnetic material on a magnetic film, specially adapted for a thin magnetic film in patterns, e.g. by lithography
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/1278—Structure or manufacture of heads, e.g. inductive specially adapted for magnetisations perpendicular to the surface of the record carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3163—Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49036—Fabricating head structure or component thereof including measuring or testing
- Y10T29/49041—Fabricating head structure or component thereof including measuring or testing with significant slider/housing shaping or treating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49036—Fabricating head structure or component thereof including measuring or testing
- Y10T29/49043—Depositing magnetic layer or coating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49036—Fabricating head structure or component thereof including measuring or testing
- Y10T29/49043—Depositing magnetic layer or coating
- Y10T29/49046—Depositing magnetic layer or coating with etching or machining of magnetic material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49048—Machining magnetic material [e.g., grinding, etching, polishing]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49048—Machining magnetic material [e.g., grinding, etching, polishing]
- Y10T29/49052—Machining magnetic material [e.g., grinding, etching, polishing] by etching
Definitions
- the invention relates to the field of magnetic data storage devices and more particularly to methods for fabricating magnetic heads for use in magnetic data storage devices and even more particularly to methods for fabricating magnetic heads with recessed surfaces around the active writing elements on the ABS.
- FIG. 1 Selected components in a typical prior art magnetic storage device (disk drive) 10 are illustrated in FIG. 1 in simplified block form. Although only one disk 16 and one slider 11 are shown, there may be multiple disks in a drive and typically there are two sliders per disk, i.e., one for each surface of the disk.
- This disk drive comprises a thin film magnetic disk 16 for recording data, a slider or magnetic head 11 that carries out the reading and writing of data in tracks on the magnetic disk 16 .
- the disk is attached to spindle 18 which is rotated by spindle motor 14 .
- the slider includes a read head 12 and a write head 19 which are attached to suspension 13 .
- the disk 16 includes a plurality of thin films 17 in which magnetic transitions are recorded.
- Sliders are fabricated in sets on a wafer using semiconductor-type processing methods.
- the read head is formed first, but the write head can also be fabricated first.
- the conventional write head is inductive.
- the layers and structures in the sliders are first deposited on the wafer, then the wafer is sliced into rows or individual sliders to expose the transducer elements.
- the cut surfaces of the sliders are typically lapped and a protective overcoat is deposited on the air-bearing surface.
- a slider is formed with an aerodynamic pattern of protrusions (air-bearing features) on the air-bearing surface (ABS) which enable the slider to fly at a constant height close to the disk during operation of the disk drive.
- ABS air-bearing surface
- the recording density of a magnetic disk drive is limited by the distance between the read and write heads and the magnetic media. Smaller spacing or “fly height” is desired to increase the recording density.
- the magnetic domains in the media on can be written longitudinally or perpendicularly
- the recording head In a disk drive using perpendicular recording, the recording head is designed to direct magnetic flux through the recording layer in a direction which is generally perpendicular to the plane of the disk.
- the disk for perpendicular recording has a hard magnetic recording layer and a magnetically soft underlayer.
- magnetic flux is directed from the main pole of the recording head perpendicularly through the hard magnetic recording layer, then into the plane of the soft underlayer and back to the return pole in the recording head.
- an overlayer is applied over the pole tip structure, filling the recessed trenches.
- the coated structure is then trimmed to remove all coating material overlying the shield/pole and pole. Trimming is continued to additionally remove a top layer of the protrusions of the pole and shield/pole to remove any rounded edges created by pole tip patterning, resulting in a more distinct write head.
- the refilled trenches of the recessed areas impart improved resistance to corrosive attack, to head-crashes from the release of accumulated debris, and to mechanical damage of the trimmed pole-tip structure.
- a process of milling pole tip in a write head for longitudinal recording is described.
- a thin film protective layer is deposited upon the pole tip on the ABS surface.
- the FIB tool is utilized to mill the areas within the milling boxes as was done in the prior art.
- the improvement that results from the protective layer of the invention is a reduction in the rounding of the edges.
- the protective layer is removed from the head by such means as a chemical etch, burnishing or other generally known methods.
- Ferrofluids are liquids with ferromagnetic particles suspended in them.
- One use of ferrofluids is to visualize the recorded pattern on magnetic disks or for magnetic flaw detection.
- U.S. Pat. No. 4,946,613 to Ishikawa Aug. 7, 1990 describes photosetting ferrofluid compositions that include photosetting resin.
- the carrier itself includes a photosetting resin.
- the ferrofluid uses a carrier of low viscosity. By virtue of the use of a low viscosity carrier, the ferrofluid swells up with steep inclinations. Subsequently, a light beam of a specific wave length sufficient for setting the photosetting resin added in the ferrofluid as a pattern fixing agent is directed to the fluid so as to fix the pattern formed by the ferrofluid.
- ferrofluids have also been described in connection with the creation of self-aligning masks for optical masking and chemical masking.
- Yellen, et al. described the use of nanometer sized ferrofluids with alignment marks on a substrate and an applied external field.
- Programmable Self-Aligning Ferrofluid Masks for Lithographic Applications IEEE Transactions On Magnetics, vol. 40, no. 4 July 2004.
- the ferrofluid particles are preferentially deposited over one of the poles of ferromagnetic islands which are used as the alignment marks.
- One embodiment of the invention is a method for fabricating sliders (magnetic heads) with a recessed surface around a magnetic feature such as the active components of the write head on the air-bearing surface (ABS).
- An embodiment of the method applies a positive photoresist to the exposed surface with the write head elements on the ABS after the sliders have been cut from the wafer into rows or individual sliders.
- a magnetic field is preferably applied perpendicular to the ABS surface, then a liquid ferrofluid is applied on top of the photoresist.
- the magnetic field is applied by a permanent magnetic positioned behind the sliders in one embodiment.
- the main pole piece and the return pole piece around the write gap will interact with the applied magnetic field to make the field gradient highest around the write gap, so that the mobile ferrofluid will preferentially collect in the areas of the surface having the highest magnetic field gradient.
- the ferrofluid is allowed to dry the magnetic field can be removed.
- the opaque magnetic particles in the ferrofluid form an optical ferrofluid mask over the photoresist above the write gap.
- the slider is then exposed to the appropriate light for the photoresist.
- the ferrofluid mask around the write gap prevents the underlying photoresist from being affected by the light.
- the exposed photoresist is then developed and removed leaving the masked area of photoresist around the write gap in place.
- the surface of the slider is milled which results in the recession of material around the gap.
- the photoresist mask is then removed.
- a protective overcoat can be applied on the slider surface.
- the invention can be used with a variety of write head designs.
- the write head structure at the ABS includes the main pole, the write gap and a high moment cap which is part of the return pole structure.
- FIG. 1 illustrates relevant components in a typical prior art disk drive in simplified form.
- FIG. 2 illustrates a section view, perpendicular to the ABS, of selected components of a slider design that can be fabricated using the process of the invention.
- FIG. 3 illustrates a view of the ABS of a slider prior to being processed according to the invention.
- FIG. 4A illustrates a view of the ABS of a slider after the mask on the ABS has been patterned according to the invention.
- FIG. 4B illustrates a section view of the slider, perpendicular to the ABS, after the mask on the ABS has been patterned according to the invention.
- FIG. 5 is a flowchart of steps in a method embodying the invention.
- FIG. 6 illustrates a slider carrier and permanent magnet used in an embodiment of the invention.
- the method of the invention has general applicability to fabrication of magnetic heads which have ferromagnetic structures on the surface that concentrate ferrofluid in an applied magnetic field; therefore, the invention can be used with any write head design.
- the embodiment of the invention described below uses a write head for perpendicular recording with a particular design that includes a pedestal and a high moment cap as part of the return pole.
- FIG. 2 illustrates a partial section of a particular embodiment of a slider 11 having a write head 19 which can be fabricated using the method of the invention. The section is perpendicular to the air-bearing surface (ABS) on the right of the figure. With the exception of the S2 shield 21 the read head is not shown. Any read head design can be used with the invention.
- ABS air-bearing surface
- the P1 pole 23 of the write head is separated from the S2 shield by gap layer 22 .
- the pedestal pole piece 24 extends from P1 to the pedestal cap 25 which is made of a high moment material.
- the write gap 26 separates the pedestal cap 25 from the main pole piece 27 .
- the write head includes P3 pole piece 28 and coil 29 .
- the embodiment shown in FIG. 2 has the surfaces around the pedestal cap 25 , write gap 26 and main pole piece 27 recessed in order to bring the active pole elements closer to the disk surface during operation.
- the method of the invention described below deals with the process of forming the recessed area. Except for the recessed areas, the structures of the head are formed according to the prior art.
- FIG. 3 illustrates an ABS view of the slider prior to being processed by the invention.
- the slider 11 has been cut from the wafer to expose the surfaces depicted in FIG. 3 . If lapping is included in the process of making the slider, it must be completed prior to beginning the process of recessing the surfaces according to the invention.
- FIG. 4A illustrates the ABS of the slider after mask 34 has been patterned using photoresist and ferrofluid according to the invention.
- FIG. 4B illustrates a section view of the slider, perpendicular to the ABS, after the mask 34 on the ABS has been patterned according to the invention.
- FIG. 4B shows that the mask 34 includes a photoresist portion 34 P and a ferrofluid mask portion 34 F.
- FIG. 5 is a flowchart of a method embodying the invention.
- the sliders are cut from the wafer and optionally lapped 40 .
- the sliders can be cut into rows or individual sliders.
- the process is preferably carried out in a clean-room.
- the sliders are preferably placed in a carrier and fixed in place by forming a matrix of a glue-like material around them 41 .
- the matrix is formed by prior art methods and will typically include pouring a liquid around the sides of the sliders. The glue-like liquid will then harden to firmly hold the sliders in position.
- the tops of the sliders have the exposed thin film features.
- the tops of the sliders must remain exposed for processing.
- a positive photoresist is applied to the set of sliders in the carrier preferably by spinning on the liquid photoresist 42 .
- the photoresist will eventually become the portion of the mask shown as 34 P in FIG. 4B .
- a magnetic field is applied to the sliders 43 .
- the magnetic field is oriented perpendicular to the surface of the sliders having the thin film magnetic features.
- One method of applying this field is to place a permanent magnet behind the carrier.
- the permanent magnet needs to be large enough to apply a reasonably uniform magnetic field to each of the sliders in the carrier.
- An electromagnetic apparatus can also be used to apply the field.
- the ferrofluid is then applied to the surface and allowed to dry 44 .
- ferrofluids There are numerous types of ferrofluids that are commercially available. Any colloidal suspension of the Fe 2 O 3 particles with diameters about 10 nm which are surface passivated and are a colloidal suspension in water-, alcohol-, or glycerin-based solution can be used.
- ferrofluids One family of commercially available ferrofluids that are useful for this application are the aqueous-based EMG-series ferrofluids from Ferrotec, 40 Simon Street, Nashua, N.H. 03060-3075.
- the ferrofluid can be applied by any appropriate means including being spun on or applied with pen-sponge.
- the ferrofluid will preferentially collect in the areas with the highest magnetic field gradient.
- the gradient will be highest in the area of the write gap due to inherent design of the write head.
- a smaller amount of ferrofluid will collect in the read gap where the gradients are weaker.
- the ferrofluid in the read gap is not a problem, since it is acceptable for this area to be masked and not to be milled.
- the photoresist is ready for exposure which can be achieved by flood lighting.
- the ferrofluid over the write gap masks the underlying photoresist from exposure.
- the photoresist is then developed 45 .
- the exposed photoresist is removed leaving only the areas masked by the ferrofluid 46 .
- the surface of the slider around the mask is milled using one of the available techniques such as reactive-ion-etching (RIE) or ion-milling.
- RIE reactive-ion-etching
- the depth of material removed can be controlled by timing. For the slider design in this example, a recession depth of about 0.3 microns is reasonable.
- the ferrofluid mask on top of the photoresist has different characteristics than the underlying photoresist, so a separate step in the process may be needed to remove the ferrofluid first 48 .
- Water or alcohol may be sufficient to remove the dry ferrofluid, but the exact technique needed will be determined by the characteristics of the particular ferrofluid used.
- the photoresist can then be removed by chemical stripping or other prior art means 49 .
- the prior art processing of the slider is resumed at this point and can include deposition of an overcoat.
- FIG. 6 illustrates a simple configuration of a carrier 51 which is in contact with permanent magnet 52 for the phase of the process when the ferrofluid is being applied and dried.
- the sliders 54 can be rows or single sliders which are embedded in matrix material 53 which can be a glue-like material which is poured around the sliders and hardened.
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- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
- Magnetic Heads (AREA)
Abstract
Description
Claims (20)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US11/391,069 US7526856B2 (en) | 2006-03-27 | 2006-03-27 | Method for fabricating a magnetic head using a ferrofluid mask |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US11/391,069 US7526856B2 (en) | 2006-03-27 | 2006-03-27 | Method for fabricating a magnetic head using a ferrofluid mask |
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US20070220739A1 US20070220739A1 (en) | 2007-09-27 |
US7526856B2 true US7526856B2 (en) | 2009-05-05 |
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US11/391,069 Expired - Fee Related US7526856B2 (en) | 2006-03-27 | 2006-03-27 | Method for fabricating a magnetic head using a ferrofluid mask |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8599653B1 (en) | 2012-09-11 | 2013-12-03 | Western Digital Technologies, Inc. | Systems and methods for reducing condensation along a slider air bearing surface in energy assisted magnetic recording |
US8988830B1 (en) | 2013-05-13 | 2015-03-24 | Western Digital (Fremont), Llc | Air bearing design to mitigate lube waterfall effect |
US20160118064A1 (en) * | 2013-03-15 | 2016-04-28 | Seagate Technology Llc | Write head core |
US11498270B2 (en) | 2018-11-21 | 2022-11-15 | Toyota Motor Engineering & Manufacturing North America, Inc. | Programmable matter |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4946613A (en) | 1987-03-27 | 1990-08-07 | Nippon Seiko Kabushiki Kaisha | Photosetting ferrofluid compositions |
JPH11134618A (en) * | 1997-10-28 | 1999-05-21 | Nec Ibaraki Ltd | Manufacture of mr composite head and mr composite head by this |
US5916641A (en) | 1996-08-01 | 1999-06-29 | Loctite (Ireland) Limited | Method of forming a monolayer of particles |
US6174449B1 (en) | 1998-05-14 | 2001-01-16 | Micron Technology, Inc. | Magnetically patterned etch mask |
US6180226B1 (en) | 1996-08-01 | 2001-01-30 | Loctite (R&D) Limited | Method of forming a monolayer of particles, and products formed thereby |
US6402876B1 (en) | 1997-08-01 | 2002-06-11 | Loctite (R&D) Ireland | Method of forming a monolayer of particles, and products formed thereby |
US6423172B1 (en) | 1998-01-30 | 2002-07-23 | Loctite (R&D) Limited | Method of forming a coating onto a non-random monolayer of particles, and products formed thereby |
US6526649B2 (en) * | 2000-06-02 | 2003-03-04 | Sony Corporation | Manufacturing method of magneto-resistive effect type head |
US6584676B1 (en) | 1998-07-24 | 2003-07-01 | International Business Machines Corporation | Method for manufacturing a pole tip trimmed read/write head structure |
US20050073775A1 (en) | 2000-10-06 | 2005-04-07 | Chang Thomas Young | Pole tip trimmed magnetic recording head with minimal edge rounding |
-
2006
- 2006-03-27 US US11/391,069 patent/US7526856B2/en not_active Expired - Fee Related
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4946613A (en) | 1987-03-27 | 1990-08-07 | Nippon Seiko Kabushiki Kaisha | Photosetting ferrofluid compositions |
US5916641A (en) | 1996-08-01 | 1999-06-29 | Loctite (Ireland) Limited | Method of forming a monolayer of particles |
US6180226B1 (en) | 1996-08-01 | 2001-01-30 | Loctite (R&D) Limited | Method of forming a monolayer of particles, and products formed thereby |
US6402876B1 (en) | 1997-08-01 | 2002-06-11 | Loctite (R&D) Ireland | Method of forming a monolayer of particles, and products formed thereby |
JPH11134618A (en) * | 1997-10-28 | 1999-05-21 | Nec Ibaraki Ltd | Manufacture of mr composite head and mr composite head by this |
US6423172B1 (en) | 1998-01-30 | 2002-07-23 | Loctite (R&D) Limited | Method of forming a coating onto a non-random monolayer of particles, and products formed thereby |
US6174449B1 (en) | 1998-05-14 | 2001-01-16 | Micron Technology, Inc. | Magnetically patterned etch mask |
US6584676B1 (en) | 1998-07-24 | 2003-07-01 | International Business Machines Corporation | Method for manufacturing a pole tip trimmed read/write head structure |
US6526649B2 (en) * | 2000-06-02 | 2003-03-04 | Sony Corporation | Manufacturing method of magneto-resistive effect type head |
US20050073775A1 (en) | 2000-10-06 | 2005-04-07 | Chang Thomas Young | Pole tip trimmed magnetic recording head with minimal edge rounding |
Non-Patent Citations (3)
Title |
---|
Anonymous, Ferrofluid Patterning Optical Images, Internet ref. http://www.pages.drexel.edu/~bby22/ferrofluid-patterning accessed on Oct. 10, 2004. |
Lin et al., "Effects of Current and Frequency on Write, Read, and Erase Widths for Thin-Film Inductive and Magnetoresistive Heads", IEEE Transactions on Magnetics, vol. 25, No. 1, Jan. 1990, pp. 710-715. * |
Yellen, Friedman and Barbee, "Programmable Self-Aligning Ferrofluid Masks for Lithographic Applications," IEEE Trans. Mag. vol. 40, No. 4, Jul. 2004. |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8599653B1 (en) | 2012-09-11 | 2013-12-03 | Western Digital Technologies, Inc. | Systems and methods for reducing condensation along a slider air bearing surface in energy assisted magnetic recording |
US20160118064A1 (en) * | 2013-03-15 | 2016-04-28 | Seagate Technology Llc | Write head core |
US9922669B2 (en) * | 2013-03-15 | 2018-03-20 | Seagate Technology Llc | Method of making a write head core |
US8988830B1 (en) | 2013-05-13 | 2015-03-24 | Western Digital (Fremont), Llc | Air bearing design to mitigate lube waterfall effect |
US11498270B2 (en) | 2018-11-21 | 2022-11-15 | Toyota Motor Engineering & Manufacturing North America, Inc. | Programmable matter |
Also Published As
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US20070220739A1 (en) | 2007-09-27 |
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